Ecosystem Structure and Components — NEET Biology
📚 Practice ConceptAn ecosystem is a structural and functional unit of nature and it comprises abiotic and biotic components. Abiotic components are inorganic materials- air, water and soil, whereas biotic components are producers, consumers and decomposers. Each ecosystem has characteristic physical structure resulting from interaction amongst abiotic and biotic components. Species composition and stratification are the two main structural features of an ecosystem. Based on source of nutrition every organism occupies a place in an ecosystem.
Which of the following statements regarding the structure and function of an ecosystem are NOT correct? S1. The species composition of an ecosystem is solely determined by the types of plants, with animal species playing a secondary role. S2. Stratification is an example of a functional aspect of an ecosystem, illustrating the dynamics of energy transfer between trophic levels. S3. Biotic and abiotic components interact to create a characteristic physical structure for each ecosystem, but this interaction is not crucial for its overall function. S4. Productivity, decomposition, energy flow, and nutrient cycling are the four fundamental structural components of any ecosystem. S5. The top vertical strata in a forest are typically occupied by herbs and grasses due to their requirement for maximum sunlight.
View solution & NCERT explanation
Correct answer: D — All S1, S2, S3, S4 and S5
The question asks to identify statements that are NOT correct concerning the structure and function of an ecosystem based on NCERT text. S1. Not correct: NCERT states, "Identification and enumeration of plant and animal species of an ecosystem gives its species composition." Therefore, species composition involves both plants and animals, and animals do not play a secondary role. S2. Not correct: Stratification is a structural feature of an ecosystem, defined as the "Vertical distribution of different species occupying different levels." Energy transfer between trophic levels is a functional aspect (energy flow), not stratification itself. S3. Not correct: NCERT clearly states, "Interaction of biotic and abiotic components result in a physical structure that is characteristic for each type of ecosystem." This interaction is fundamental and crucial for the ecosystem's overall function and sustainability. S4. Not correct: Productivity, decomposition, energy flow, and nutrient cycling are listed in NCERT as the four fundamental *functional aspects* of an ecosystem, not its structural components. The structure is defined by species composition and stratification. S5. Not correct: NCERT specifies, "trees occupy top vertical strata or layer of a forest," while "herbs and grasses occupy the bottom layers." Trees, not herbs and grasses, occupy the top strata, and they are adapted to maximum sunlight. Since all statements (S1, S2, S3, S4, and S5) are incorrect, the correct option is D.
What does NCERT say about ecosystem structural and functional?
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